By the time she was 24, she was already comfortable walking the red carpet at the Oscars.

Then, as abruptly as she started, she stopped.

And the woman who starred with Elvis in two movies and was contracted to star with Marlon Brando for huge bucks in her next film stopped making movies and stopped walking red carpets.

In fact, she didn’t make another movie or walk another red carpet for 50 years.

I’m talking about Mother Prioress, formerly known as teen-queen movie star Dolores Hart, who walked into the cloistered Abbey of Regina Laudis, in (I swear!) Bethlehem, Conn., in 1963, where she took the veil and never looked back.

Well, she did look back, butshe never left.

But this year, an HBO documentary, “God Is the Bigger Elvis,” was nominated for an Academy Award, and Dolores Hart found herself once again walking the red carper (in her traditional Benedictine habit) at the Oscars, although not one single reporter was clever enough to ask her “Who are you wearing?”

Her answer, I suspect, would have been “Bride of Jesus.”

After reading my review of the extraordinary documentary in The Post, Mother invited me up to the monastery for a weekend. And I went.

In fact, I drove up Friday afternoon and found myself not in a 12th Century fortress, but in a bucolic farm. Talk about a whole new meaning to “Girls Weekend!”

I met Mother Dolores, now 74, in a little closed-off area, where guests eat meals separate from the nuns.

We talked for hours. The woman who’d kissed Elvis and left her fiance for the altar, says none of it was easy. In fact, she was miserable for a long while.

Leaving Hollywood was rough. “My boss, Hal Wallis, told me, ‘Don’t bother coming back to Hollywood. I will never let you work again,’ ” she said, still pained by the sting.

And her agent? He gave her a gold razor blade, and said,“You’ve committed suicide.”

Not that her life before that had been easy.

Her father, whom she described as “gorgeous,” was a bit actor and an abusive drunk.

When she was 6, he showed up on Christmas (her parents divorced and remarried several times) in a Santa suit. He then proceeded to break her mother’s jaw while little Dolores hid in the closet.

“I had been learning a new word everyday, and wrote a letter to my grandmother, saying, ‘This is not a good environment for me!’ ”

But Mother Prioress isn’t the only nun there with an interesting — very interesting — past.

One beauty, who works the fields in (yes) a denim habit, is 44-year-old Laura Adshead. Back in the early 1990s, she was in a relationship with now-British Prime Minister, David Cameron, went on to a career in advertising in Manhattan, and just recently decided to join the abbey.

Then there’s firecracker nun, Mother Angele, a 64-year-old who looks 40. She was raised Jewish, and was a music manager before giving it up 14 years ago to become a nun.

We ate, we laughed, we joked, they chanted and prayed and stood behind wooden gratings. But, make no mistake, they fly even with their wings clipped.